Photographic printing paper



'July 4, 1933.

M. HEINRICH 1,917,032

PHOTOGRAPHI C PRI NTI NG PAPER Filed July 10, 1931 Patented July 4, 1933 UNITED-"STATES PATENT oFrlcE nmx nnnmrcn, or" nnnn n-mnxow, GERMANY, assienon 'ro'rrnir can UN!) 00..

' VERPAOKUNGS-MASCHINEN, OI BERLIN, GERMANY PR-ElSSllED rnoroenumc PRINTING rnnn Application filed July 10, 1931, Serial No. 549,866, and in Germany July 12, 1980.

' This invention relates to a photographic printing paper, especially for making copies of drawings, and consists essentially in providiiig possibilities for making drawings or photographic prints by imeansof a metal foil backmg fastened ori-the rear of the original drawing" and by means of a sheet of I copying paper .shown an example of my new photographic paper for making drawings or photographic prints according to my present invention, Fig. 1 being a section showing the several layers of w ich the newk 'aper is composed, F1g.2 a top-view on showing in particular the paper accordin to Fig. 1 with a drawing of a work piece thereon and Figs 3 a longitudinal section through Fig. 2.

The-"new photographic printing paper which forms part of my present invention consists of the sheet d which is the drawing sheet proper, a backing consisting of metal foilsg-a and b applied to said sheet d by a processof hard rolling, and the light-sens? tive layer 0. The sheet (I may be fastened to the backing a and b by means of a paste 'or applied thereto in liquid condition.

I More particularly, the drawing sheet d tserves-gfor protecting the backing a ariifb which consists of aluminum against decomposing if the photographic print is developed y'ni'eans' of anacid ,or salt. Drawings may e made onthedi'aw'ing sheet or protective matter of What kind the latter may f ncilfor drawing ink and sheet.

fixed to the outer surface of also erasures may. be madeon' said drawing As aluminum at a mm. can only be rolled in widths of froni -60 cm. it would be impossible to make photographic printingpapers of the present kind of a width exceeding these dimensions. In order to permit the maki'ngof photographic printing papers of a greater width-Y than about 50-60 cm., I further propose to .niake up the aforementioned. backing of a plurality of sheets a and b of metal foil and to make the abutting edges of said sheets a and b of wave-shaped or dovetail conformation, as shown at f, f in,Fig. 2. 'The wavethickness of about 0.04 I I shaped edges along which the metal sheets or layers a and Irabut as shown in Figs. 1, 2 and 3 are possessed of the great advantage that they ermit to make copies of drawings of any desired width by placing a plurality of such metal sheets or layers having a limited width side by side with their.wave-shaped edgesabutting, therebyrendering it POSSl? ble to make drawing templates for workpieces of any desired size. The form ofthe wave-shaped edges fmay besomewhat difl'erent from that shown in the drawing. More particularly, said wave-shaped edges may be of the form of sine-curves of any esired am litude, that is said edges are. not necessarily of the specific shape of serpentine lines as shown in Fig. 2 of the drawing. When using edges fof the form olts a sine or similar curve, the curve may 'a o be more flat-. tened or more pointed. The wave-shaped edges ffurthermore'serveto revent e'rforation of the paper when makin a drawing thereon or torevent breakin uring being folded, such re'akin bein iable to occur in case'sheets are use whic abut with each other along straight edges.

Connecting the two sheets a and I) along wave-shaped edges, as compared with overlapping edges, is possessed of the advantage that the drawing surface proper will be fully plane. The lines of the drawing, evidently will intersect the edges which abut with each other along any kind of wave-shaped lines only at oints, while, in case of strai ht edges or over apping edges the lines of the drawing will intersect the abutting parts of the two sheets along a greater or even the entire length which may eventually result in tearing up the backing a, b.

The novel effect which may be attained by my present invention may be clearly seen from Fig. 2. In Fig. 2 g designates the drawing of an angle-iron with holes, h, 72, 71 h, and h are the imaginary points of intersection between the wave-shaped edges 7' of the metal foils and the border lines of said angle-iron. It will be seen that the angles of the intersection between said border lines and said wave-shaped edges are all very nearly right angles, with the result that during the process of copying the drawing cannot be distorted by warping or the like.

I claim:

As an article of manufacture, a photographic printing paper, especially for making copies of drawings, said paper consisting of a light-sensitive sheet, a metal foil backing fastened to the rear surface of said light sensitive sheet, said metal foil backing being composed of several pieces placed side by side and abutting with each other along wave-shaped edges, and a sheet of drawing paper fastened to the rear surface of said metal foil backing.

In testimony whereof I afiix my signature.

MAX HEINRICH. 

